Fireproof,thermoplastic polyester-polyaryl phosphonate composition

ABSTRACT

A fireproof, thermoplastic polyester composition which comprises a polyester and a polyaryl phosphonate incorporated therein in an amount of 0.4 to 4.0 weight percent as phosphorus to the polyester, the said polyaryl phosphonate being not less than 6 in the degree of polymerization and containing as its diol component a sulfone compound of the formula:   WHEREIN THE BENZENE RING(S) MAY BEAR ONE OR MORE LOWER ALKYL GROUPS WITH OR WITHOUT ANY OTHER DIOL COMPOUND.

United States Patent 1 1 Masai et al.

1 1 FIREPROOF, THERMOPLASTIC POLYESTER-POLYARYL PIIOSPIIONATE COMPOSITION [75] Inventors: Yukito Masai, Otsu-shi; Yasuo Kato,

Shiga-gun; Nobuhiko Fukui, 'Otsushi, all of Japan [73] Assignee: Toyo Boseki Kabushiki Kaisha (Toyo Spinning Co., Ltd.), Kita-ku, Osaka-shi, Osaka-fu, Japan 221 Filed: March 18,1971

211 Appl.No'.: 125,709

[30] Foreign Application Priority Data 1 March 6, 1973 11/1966 Gillham et a1 ..260/45 7 PS 9/1967 Gillham et a1 ..26()/45.7 PS

Primary Examiner-Wil1iam H. Short Assistant Examiner-Edward Woodberry Attorney-Craig, Antonelli, Stewart & Hill 5 7 ABSTRACT HO OH March 19, 1970 Japan ..45/23910 Q Q ll [52] US. Cl. ..260/860, 260/45.7 PS, 260/49 0 III- wherein the benzene ring(s) may bear one or more [58] Field of Search ..260/860, 49, 45.7 PS lower alkyl groups with or without any other diol compound. [56] References Cited UNITED STATES PATENTS 13 Claims, 1 Drawing Figure 2,682,522 6/1954 Coover et a1. ..260/49 PATENTED 61373 3,719,727

HWEMTOE': YUKITO MASAI YASUO KATO NOBUHIKO FUKUI ATTORNEYS FHREPROOF, THERMOPLASTIC POLYESTER- POLYARYL PHOSPHONATE COMPOSITION For giving a fireproof property to polyesters, various compounds such as halogen compounds, phosphorus compounds and metal compounds have heretofore been incorporated into polyesters. Among them, esters of phosphoric acid, phosphorous acid and phosphonic acid containing or not halogen atoms afford a relatively high fireproof property to polyesters. However, when a polyester incorporated with such ester is subjected to melt moulding, for example, melt spinning, ester exchange takes place betweenthe polyester and the ester whereby the polymerization degree and the melt viscosity of the polyester are lowered. Consequently, spinning can hardly be performed, or even if performed, the resulting filaments are inferior in the quality and meet troublesome problems onthe practical use.

The thermoplastic polyester composition according to the present-invention comprises a polyester and a polyaryl phosphonate incorporated therein in an amountof 0.4 to 4.0 weight percent as phosphorus to the polyester, the said polyaryl phosphonatebeing not less than 6 in the degree of polymerization and containing as its diol component a sulfone compound of the formula:

HO OH,

wherein the benzene ring'(s) may bear one or more lower alkyl groups with or without at least one of the aromatic diol compounds of the formulae:

HO OH HO OH HO OH Q {III} HO OH at least one of the aromatic diol compounds [I] to [IV] with a compound of the formula:

wherein R is aryl (e.g. phenyl, tolyl, xylyl, naphthyl) and X is chlorine or bromine. The reaction may be executed by heating a mixture of these reactants in approximately equimolar amounts at to 200C under atmospheric pressure and then at to 250C under atmospheric or reduced pressure in an inert gas or dry air, preferably in the presenceof a catalyst such as magnesium chloride or calcium chloride. Alternatively, the reaction may be carried out by surface polymerization of the compound [V] dissolved in a solvent such as methylene chloride with the sulfone compound [A] or its mixture with at least one of the aromatic diol compounds [I] to [IV] as alkali metal salt(s) dissolved in water while stirring.

Examples of the sulfone compound [A] are 4,4- dihydroxydiphenyl sulfone, 2,4-dihydroxydiphenyl sulfone, 3,3'-dimethyl-4,4'-dihydroxydiphenyl sulfone, 2,2'-dimethyl 4,4'-dihydroxy-5,5'-di-t-butyldiphenyl sulfone, 2,2'-dihydroxy-3,3'-dimethyldiphenyl sulfone, 3,3, 5 '-tetramethyl-4,'-dihydroxydiphenyl sulfone, etc.

Examples of the aromatic diol compounds [I] to [IV] are hydroquinone, resorcinol, 4,4'-dihydroxybiphenyl, 4,4'-methylenebisphenol, 4,4'-ethylidenebisphenol, 4,4'-isopropylidenebisphenol, cyclohexlidenebisphenol, 2,2-methylenebisphenol, l,S-dihydroxynaphthalene, 2,7-dihydroxynaphthalene,

etc. v

Examples of the compound [V] phenyldichlorophosphine oxide, phenyldibromophosphine oxide, etc.

The polyaryl phosphonate to beused in this invention is required to be not less than 6 inthe degree of polymerization when calculated from the molecular weight which is determined by the vapor pressure osmometry using chloroform as a solvent at 35C. Particularly preferred is the one, of which the'degree of polymerization is 10 or more. When the degree of polymerization is below 6, the polyaryl phosphonate is not stable and the viscosity of the polyester incorporated therewith is considerably lowered.

in general, the polyaryl phosphonate having a sulfonyl group in its molecular chain reveals a better fireproof property than any polyaryl phosphonate having no sulfonyl group. For preparation of the polyaryl phosphonate, the use of the sulfone compound [A] alone or together with any'other aromatic diol compound [l] to UV} containing the former in an amount above 30 mol percent, especially above 50 mol percent, to the total amount of the mixture is thus preferred.

In the composition of the invention, the amount of I the polyaryl phosphonate is 0.4 to 4.0 weight percent, preferably 0.6 to 3.0 weight percent as phosphorus to the polyester. The incorporation of the polyaryl phosphonate into the polyester is preferably carried out after the polycondensation of the polyester is completed.

According to this invention, various thermoplastic polyesters can be made non-inflammable. For example, polyethylene terephthalate, fiber-forming copolymerized polyester containing not less than 80 mol percent of ethylene terephthalate unit, poly-l,4- cyclohexylidenedimethylene terephathalate, polyethylene sebacate, polyethylene adipate and the like are advantageously provided with a fireproof property.

On the'incorporation of the polyaryl phosphonate into the polyester for melt spinning, it is desirable to place the former under the melt condition as shortly as possible. Further, it is favorable to add the polyaryl phosphonate to the polyester after completion of the polymerization and just before the spinning. When the addition is performed at the beginning or middle stage of polymerization, coloring of 'the polyester may be caused, and the completion of the reaction will be delayed. The addition at the final stage of polymerization may lower the viscosity of the polyester and will in-- crease the coloring of the product by ultraviolet ray.

The polyaryl phosphonate may be employed in the form of pellet. For preparation of pellets, the polyaryl phosphonate is melt polymerized, extruded out of a nozzle at the bottom of the reaction vessel under the pressure of nitrogen and out while hot to give pellets. Alternatively, a solution of the polyaryl phosphonate in a soluble solvent (e.g. chloroform, tetrachloroethane) is poured into an insoluble solvent (e.g. methanol), and the precipitated powder is moulded in pellets, after tableted as the case may be, by the aid of an extruder.

The mixture of the polyester and the polyaryl phosphonate may be subjected to melt spinning as such or preferably after moulded in pellets by the aid of a pelletizer to give filaments, which are scarcely colored or lowered in the degree of polymerization and hardly colored by ultraviolet ray. Still, the polyaryl phosphonate may alternatively be incorporated into the polyester in a meltedstate during spinning.

The polyester composition of the present invention possesses an excellent fireproof property and shows a good affinity to cationic dyes and dispersion dyes and a sufficient pilling resistance after dyeing at high temperature and bleaching.

Practical and presently preferred embodiments of lowing Examples wherein parts are by weight.

I the present invention are illustratively shown in the folln vthesez-Examples, the intrinsic viscosity of the polyester is measured in a phenol-tetrachloroethane mixture (3:2) at 30C.

The non-inflammability is estimated using an apparatus shown in FIG. 1 of the attached drawing in the following manner: 1

l. The flame-remaining time and the ratio of unburnt residue: The test composition (1 g) in powder of about 20 mesh is charged in a conical vessel 1 made of stainless steel wire -No. '36 mesh). The bottom of the vessel is contacted for 20 seconds with a butane gas flame 3 containing air which is introduced from a hole of 2 mm in diameter by the use ofa microburner 2 of 6 mm in hole diameter. The shape of the vesseLthe bulk of the flame and the distance between the bottom of thevessel and the flame are as shown in FIG. 1. The temperature of the upper part of the flame which is contacted with the'vessel is about 750C; A partof the test composition is melted and drops into an aluminum foil 4. The unburnt residue present in the wire vessel and in the alumin um foil is weighed, and the ratio by weight percent to the initial weight of the test composition as well as the flame-remaining time after removal of the tire are used for estimation of the non-inflammability.

2. The coil method: A plain fabric of filaments made of the test composition and being 10 cm in width and l g in weight is rolled and inserted into a supporting coil made of hard stainless steel and being 10 mm in inner diameter, 2 mm in interval and 15 cm in length. The coil is hung in a draft-proof chamber at an angle of 45 degrees. The test composition is ignited with a burner set up in such a manner that the top of the flame of 45 mm in length is contacted with the bottom of the test composition. As the fuel, liquefied petroleum gas is employed. Ignition is continued until combustion of the test material ceases. Then, the coilis contacted with the flame until the lower part of 9 cm in length of the test material is completely burnt. When the contact times with the flame are 3 or more, the non-inflammability of the test material is regarded as satisfactory.

3. The oxygen index n: According to the oxygen index method described in ASTM D-2863-70, the oxygen index n is determined using a sheet of plain fabric made of the test composition, being 10 cm in length and S cm in width and tightly rolled up in a sticklike shape.

The number average molecular weight of the polyaryl phosphonate is measured by the vapor pressure osmometry at 35C. in chloroform, and the degre of polymerization is determined therefrom. l

PREPARATION OF FIREPROOF AGENTS PROCEDURE] A mixture of 4,4'-dihydroxydiphenyl sulfone' (36 parts), phenyldichlorophosphine oxide (29.3 parts) and calcium chloride (0.2 part) is heated in nitrogen stream at 150C for minutes, at 1709C for 30 minutes and then at 190C for 30 minutes. After the temperature is raised up to 250C in 30 minutes, the reaction mixture is kept at this temperature for 10 minutes under a reduced pressure of about mmI-Ig. Nitrogen gas is introduced so as'to recover the at? mospheric pressure. Then, the reaction mixture is cooled to give a brown solid, which is designated as a fireproof agent A. Molecular weight, 5,800. Degree of polymerization, 15.0. M.P., 187C.

In the same manner as above but usingan equimolar amount of hydroquinone in place of 4,4'- dihydroxydiphenyl sulfone, there is prepared a polyphosphonate, which is designated as a fireproof agent X for control. Degree of polymerization, 32, M.P., C.

PROCEDURE 2 The fireproof agent A (20 g) is dissolved in chloroform (50 ml), and the resultant solution is poured into methanol (300 ml). The formed precipitate is collected, washed well with methanol, filtered and driedunder reduced pressure to give white powder (19 g), which is designated as a fireproof-agent B. Molecular weight, 7,400. Degree of polymerization, l9'.5.M-;P.,,175C. a

PROCEDURE3 A mixture of phenyldichlorophosphine oxide (1 mol), 4,4'-dihydroxydiphenyl sulfone (0.48 mol), resorcinol (0.48 mol) and a catalytic amount of calcium chloride is heated in nitrogen stream at 150C for 4 hours, at 180C for 15 hours and then under reduced pressure at 200C for 2 hours. The product is designated as a fireproof agent C. Degree of polymerization, l8. M.P., 140 to 150C.

PROCEDURE 4 A mixture of 4,4-dihydroxydiphenyl sulfone (40 parts), phenyldichlorophosphine oxide (29.3 parts) and calcium chloride (0.25 part) is heated in nitrogen stream at 150C for 90 minutes, at 180C for 30 minutes and then at 200C for 30 minutes. After the mixture is kept under reduced pressure for minutes, nitrogen gas is introduced so as to recover the atmospheric pressure. The reaction mixture is cooled to given a brown solid which is designated as a fireproof agent Y for control. Molecular weight, 2150. Degree of polymerization, 5.8. M.P., 170C.

PROCEDURE 5 PROCEDURE 6 A mixture of bis(3-methyl-4-hydrophenyl)sulfone (25 g), phenyldichlorophosphine oxide (18.3 g) and calcium chloride (100 mg) is gradually heated up to 140 to 250C in nitrogen stream in 7 hours and then heated at 260C for hours under a reduced pressure below 5 mmHg to give yellowish brown solid. Number average molecular weight, 7,300. The solid (30 g) is dissolved in chloroform (70 ml), and the resultant solution is added dropwise to methanol (700 ml) to give precipitate (27 g), which is designated as a fireproof agent E. M.P., 204C. Molecular weight, 8,900. Average degree ofpolymerization, 22.2.

PROCEDURE 7 A mixture of bis(3,5-dimethyl-4hydroxyphenyl)sul- I 'fone (15.3 g), phenyldichlorophosphine oxide (102 g) and calcium chloride (300 mg) is treated in the same manner as in Procedure 6 to give a yellowish brown solid. The solid (19 g) is dissolved in chloroform (50 ml), and the resultant solution is added dropwise to methanol (500 ml) to give white powder (15 g), which is designated as a fireproof agent F. Average molecular weight, 4,200. Average degree of polymerization, 9.7. M.P., 223C.

PROCEDURES As in Procedure 1 but using resorcinol in place of 4,4-(dihydroxydiphenyl)sulfone, there is obtained a yellow solid, which is designated as a fireproof agent Z.

PROCEDURE 9 The reaction product (molecular weight, 1 1,000) (3.5 kg) obtained in Procedure 5 is dissolved in chloroform (21 L). To the solution, methanol (17.5 L) is added, and the resultant mixture is stirred. The upper layer of the mixture is removed by decantation. The lower layer is added dropwise to methanol to give white powder (2,735 g), which is designated as a fireproof agent H. To the upper layer, methanol (2.7 L) is added, and the resultant mixture is stirred. The lower layer is concentrated under reduced pressure to give a residue, which is designated as a fireproof agent 1. The upper layer is further treated with methanol in the amount as shown in Table l in the same manner as above so as to repeat separation. The separated products are designated as foreproof agents J, K, L and M respectively. The yields and the physical prodperies of the fireproof agents are shown in Table 1.

Table 1 Fire Amount of Yield Average Average degree proof methanol added (g) molecular of polymerizaagent (L) weight tion M (Concentra- 182 1350 3.6

tion) EXAMPLE 1 Polyethylene terephthalate (intrinsic viscosity, 0.63) is pulverized in powder below 20 mesh and admixed with the fireproof agent A, B or Y. The resulting mixture is dried in a glass ampoule at to C under a pressure of 0.1 mmHg for 16 hours. The dried mixture is kneaded well at 280C for 30 minutes in nitrogen stream and then cooled to give non-inflammable polyethylene terephthalate. The intrinsic viscosity Note: The amount is by weight The parenthesized numeral represents the amount as phosphorus.

From the above Table, it is apparent that when the fireproof agent Y for control is used, the intrinsic viscosity of the resultant polyethylene terephthalate is greatly lowered, though the non-inflammability is sufficiently high.

EXAMPLE 2 Polyethylene terephthalate (intrinsic viscosity, 0.62) is pulverized in powder below 20 mesh and admixed with the fireproof agent C in an amount of weight percent (1.06 percent as phosphorus). The resultant mixture is treated in the same manner as in Example 1 except that kneading is performed at 275C for minutes to give non-inflammable polyethylene terephthalate. The intrinsic viscosity is 0.60. The flame-remaining time is 6 seconds and the ratio of the unburnt residue is 93 percent.

EXAMPLE 3 Non-inflammable polyethylene terephthalate is prepared in the same manner as in Example 2 but using the fireproof agent A or X. The non-inflammability is shown in Table 3.

Note: The amount as phosphorus is shown.

From the above Table, it is seen that the fireproof agent A is more effective than the fireproof agent X.

EXAMPLE 4 Polyethylene terephthalate pellets obtained using zinc-gelmanium as a catalyst is admixed with the fireproof agent D and dried at 105 to 110C under a pressure below 1 mmHg for 16 hours. The mixture is pelletized by the aid of an extruder of 40 mm in inner diameter wherein'the temperatures of the barrel and the nozzle are 280C with a flowing amount of 150 g/min. The obtained pellets are dried at 105 to 1 10C under a pressure of 1 mmHg for 16 hours and subjected to melt spinning by the aid of an extruder spinning machine of 30 mm in inner diameter nuder the following conditions: diameter of nozzle, 0.3 mm; number of holes, 36; spinning velocity, 900 m/min.; flowing amount, 25.5 g/min.; spinning temperature, 275C at the barrel and 280C at the nozzle. Spinning is carried out smoothly without trouble such as snapping. The ob tained filament is stretched by the aid of a stretcher wherein the temperatures of the pin and the plate are 90 and 150C respectively with a stretching velocity of 220 m/min. up the the length of 3.51 times.

For comparison, polyethylene terephthalate which is not admixed with any fireproof agent is pelletized and subject to melt spinning in the same manner as above but the temperature of the'nozzle is 292C.

The properties of the yarns thus obtained are determined, and the results are shown in Table 4.

Table 4 Test material 1 -11 Intrinsic viscosity of 0.68 0.6 polyethylene terephthalate '1] Amount of fireproof agent (parts 8 Intrinsic viscosity of polyethylene terephthalate pellets 0.65 0.62 admixed with or without fireproof agent [1 Stretched yarn Fineness (d) 2.07 2.10 Strength (g/d) 3.82 4.53 Elongation 31.5 30.4 Strength of knot (g/d) 3.34 3.93 Elongation of knot 15.3 10.7 Melting point (C) 265 260 Non-inflammability (coil method) (number of times) Before refining 6-7 l-2 After refining 6-7 1-2 After refining and bleaching 6-7 1-2 After refining, bleaching, and treatment with fluorescent dye 5 -2 After refining and dyeing 6 1-2 After dry cleaning (10 times) 6-7 1-2 After washing with soap (10 times) 6-7 1-2 Oxygen index (n 29 21 The treatments shown in the above Table are carried out as follows:

Refining: The yarn is treated with Noigen EA-120 (nonionic surfactant manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) (2 g/L) with a solution ratio of 1 50 at C for 20 minutes, washed water and dried.

Bleaching with chlorite: The yarn is treated with sodium chlorite (2 g/L) or 10 percent acetic acid (10 ml/L with a solution ratio of 1 30 at 100C for 60 minutes and washed with water. Then, the product is' treated with sodium bisulfite (2 g/L) with a solution ratio of l 50 at 70C for 20 minutes, washed with water and dried.

Treatment with fluorescent dye: The product obtained by treatment with chlorite is treated with Mikawhite ATconc" (fluorescent dye manufactured by MitsuiChemical Co., Ltd.) (1.5 owf) and Disper TL" (anionic surfactant manufactured by Meisei Chemical Co., Ltd.) (1 g/L) with a solution ratio of 1: 30 at 120C for 60 minutes, washed with water and dried.

Dyeing with dispersion dye: The refined yarn is treated with Resorcin Blue FBL (dispersion dye manufactured by Bayer A.G.) (1 owf) and Disper TL (1 g/L) with a solution ratio of l 40 at 120C for 60 minutes. Then, the product is further treated with hydrosulfite (2 g/L), sodium hydroxide (2 g/L) and A myladin" anionic surfactant manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) with a solution ration of 1 50 at C for 20 minutes, washed with water and dried.

Dry cleaning: The yarn is treated with Perclene containing Neuron NP (nonionic surfactantmanufactured by Takemoto oils and fats Co., Ltd.) (10 g/l), AD-800 (anionic surfactant manufactured by Takemoto oils and fats Co., Ltd.) (10 g/L) and water (1 ml/L) at 30C for 30 minutes and dried in an atmosphere.

Washing with soap: The yarn is washed with a 0.3 percent solution of soap with a solution ratio of 1 50 at 60C for 10 minutes'by'the aid of a washing machine, washedwith water; dehydrated and dried in hot air at 80C.

EXAMPLE As in Example 4, polyethylene terephthalate is admixed with a fireproof agent and subjected to melt spinning. The results are shown in Table 5.

Pulverized polyethylene terephthalate as in Example 2 (90 parts) is admixed with a fireproof agent (10 parts), dried in a glass ampoule at 110 to 120C under a pressure below 1 mmHg for 16 hours and kneaded at I Table 5 285C in nitrogen stream for 30 minutes. The viscosity Test material m w V W V" of the product is shown in Table 6.

Fireproof agent D D D E F Amount used (parts) 6 12 16 9 10 TABLE 6 Spinning temperature (C) 280 280 280 280 280 Fire Amount Average degree Viscosity of Stretching proof (parts) of polymerizaheated product ratio (times) 4.10 4.10 4.10 4.10 4.10 agent tion Fineness (d) 2.07 2.09 2.08 2.02 2.10 20 H 10 31.7 0.48

Strength (g/d) 4.28 4.07 3.70 4.24 4.16 I 10 12.1 0.42

Elongation 20.6 18.6 19.0 21.2 21.0 .1 10 11.6 0.42

Strength of K 10 10.7 0.41

knot (g/d) 3.76 3.58 3.25 3.73 3.66 M 10 8..

Elongation of, M 10 3.6 0.24

knot 9.2 8.0 7.5 8.5 8.8

ineltin 6in1(C) 256 248 241 256 255 Nonqngflgmmabimy As shown in the above Table the fireproof agent hav- (co ing a smaller degree of polymerization results in conz f i g siderable decrease in the viscosity of polyethylene Before refining 6 7 8 6-7 6-7 terephthalate incorporated therewith. After refining 6 7 8 6-7 67 After refining EXAMPLE 7 and bleaching 5 6 7 6-7 6-7 After r g. The composition containing a fireproof agent is subbleaching and t d 1t d t t hi E l 5 emmmwith ec e 0 nc spinn ng an s re c ng as in xampe with fluorecent The obtained yarn 1s knitted by the a1d of a knitting dye 4 4 56 5 5 machine for socks. The knitting is irradiated by ul- After refining t l t th f d t (1 th h't and dyeing S 6 7 6 6 ravioe ray M a a eorne er, an e w ieness 1s After dry cleaning determined by the aid of a spectrophotometer. The

( limes) 7 8 results are shown in Table 7.

TABLE 7 whiteness Fireprool agent Immediately after (before Alter After Amount irradiation 40 100 N0 Structure (parts) with UV ray) hours hours 1) ("1 "I s as 53 40 F OH; I OH; I 8 64 57 1| 5H3 {7H3 lt0 0 l a "I 66 40 0 I l i l1n TABLE 7-C0ntinued whiteness Fireproof agent Immediately alter(beforo Alter After Amount irradiation 40 100 No. Structure (parts) with UV ray) hours hours H .I ..P 0 0.' L I J22 Q Q -l'() so, --o-- Q O L Jar As seen in the above Table, the composition containing the fireproof agent according to the present invention is not so much colored by ultraviolet ray as in case if containing any other phosphorus compound as a fireproof agent.

EXAMPLE 8 The yarn obtained in Example 4 is immersed in a dyeing bath containing a cationic dye (2 owf), acetic acid (1.5 owf) and Emal-O (anionic surfactant I manufactured by Kao Soap Co., Ltd.) (1 g/L) with a solution'ratio of l 50 at 120C for 60 minutes. Then,

the product-is further immersed in a dyeing bath containing hydrosulfite (2 g/L), sodium hydroxide (2 g/L) and Amyladin (anionic surfactant manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 2 g/L) with a solution ratio of l 50 at 80C for minutes, washed with water and dried. The dyeing results are shown in Table Kagaku Co., (Cl Basic red 14) Ltd.

Astrazone blue G Bayer A.G. moderate stained (Cl Basic blue 1) Maxilon brilliant green 36 I Geigy A.G. moderate stained From the above Table, it is surprisingly noted that the composition of the invention (e.g. test material I possesses an affinity to a cationic dye.

EXAMPLEQ The non-inflammable polyethylene terephthalate yarn obtained in Example 4 is dyed in a dyeing bath 7 containing Mikawhite ATconc" (manufacture by Mitsui Chemical Co., Ltd.) (2.0 owf) and Disper TL" (anionic surfactant manufactured by Meisei Chemical Co., Ltd.) (1.0 g/L) with a solution ratio of 1:40 at 100C for minutes. The product (50 mg) is treated with monochlorobenzene ml), and the absorbance of the monochlorobenzene solution at 365 mp. is measured by the aid of a spectrophotometer. The results are shown in Table 9.

Table 9 Test material log T [Ill 1 I 0.362 2.15 H 0.169 1.00

As shown in the above table the coloring degree of the test material I is 2.15 times as large as that of the test material ll.

EXAMPLE The yarn obtained in Example 4 or 5 is dyed with a dispersion dye, and the reflection rate at 400 to 760 mp. of the chloroform extract of the dyed yarn is measured by the aid of a spectrophotometer. The coloring degree is determened from the reflection rate, and the results are shown in Table 10.

Tablelo Test X Y Z Relection K/S material rate (%1) at 420 my. 1 0.1041 0.0940 0.3105 29.8 0.827 ll 0.l.l85 0.l07l 0.3567 35.4 0.589 111 1.1150 0.1045 0.3441 34.2 0.633

As understood from the above Table, the composition of the invention is colored more deeply.

EXAMPLE 1 l The yarn (2.0 to 2.3 d) obtained in Example 4 and subjected to various treatments is chraged with a load of 1.3 g, and the bending timed of the yarn required for snapping are recorded. The results are shown in Table I] wherein the values are the average on 20 pieces of the yarns.

, formulas:

When the number of bending times is below 3,000, 3000, the yarn is generally thought to have a good pilling-resistant property for the practical use. Thus, the composition of the invention apprently possesses a high pining-resistant property. Further, it is notable that the pining-resistant property of the yarn becomes stronger after various treatments than before various treatments.

What is claimed is:

1. A fireproof, thermoplastic polyester composition which comprises a polyester selected from the group consisting of polyethylene terephthalate, fiber-forming copolymerized polyesters containing not less than 80 mol of ethylene terephthalate unit, polyl,4- cyclohexylidenedimethylene terephthalate, polyethylene sebacate and polyethylene adipate, and a polyaryl phosphonate incorporated therein in an amount of 0.4 to 4.0 weight percent as phosphorus to said polyester, said polyaryl phosphonate having a degree of polymerization not less than 6 and being prepared by reacting a diol component selected from the group consisting'of a sulfone compound of the forwherein the benzene ring(s) may bear one or more lower alkyl groups and a mixture of said sulfone compound and at least one aromatic diol compound of the HO ou X wherein Y is alkylidene or cycloalkylidene having one to six carbon atoms and the benzene ring(s) may bear one or more lower alkyl groups, with a compound of the formula:

wherein R is aryl and X is chlorine or bromine at to 200C. under atmospheric pressure and then at to 250C. under atmospheric pressure or reduced pressure in an inert gas or dry air.

2. The fireproof, thermoplastic polyester composition according to claim 1, wherein said sulfone compound is selected from the group consisting of 4,4-

dihydroxydiphenyl sulfone; 2,4'-dihydroxydiphenyl sulfone; 3,3-dimenthyl-4,4'-dihydroxydiphenyl sulfone', 2,2 '-dimethyl-4,4.'-dihydroxy-5 ,5 '-di-t-butyldiphenyl sulfone; 2,2-dihydroxy-3,3'-dimethyldiphenyl sulfone; and 3,3,5,5'-tetramethyl-4,4'-dihydroxydiphenyl sulfone.

3. The fireproof, thermoplastic polyester composition according to claim 1, wherein said aromatic diol compound is selected from the group consisting of hydroquinone; resorcinol; 4,4'-dihydroxybiphenyl,4,4 -methylenebisphenol; 4,4-ethylidenebisphenol; 4,4- isopropylidenebisphenol; 4,4'-cyclohexylidenebisphenol; 2,2-methylene-bisphenol, 1,5- dihydroxynaphthalene; and 2, 7-dihydroxynaphthalene 4. The fireproof, thermoplastic polyester composition according to claim 1, wherein the compound having the formula:

are reacted in approximately equimolar proportions.

7. The fireproof, thermoplastic polyester composiphosphonate is phenyldichlorophosphine oxide. 11. The fireproof, thermoplastic polyester composi I tion of claim I, wherein the diol component is said sulfone compound. v r

8. The fireproof, thermoplastic polyester composition of claim I, wherein the diol component is the mix ture of said sulfone compound and, at least one of said aromatic diols, said mixture containing more than 30 mol percent of said sulfone compound.

9. The fireproof, thermoplastic polyester composition of claim 1, wherein said sulfone compound is 4,4- dihydroxydiphenyl sulfone and said polyaryl phosphonate is phenyldich'lorophosphine oxide;

10. The fireproof, thermoplastic polyester composition of claim 9, wherein the sulfone compound is a mixture of 4,4'-dihydroxydiphenyl sulfone and 2,4- dihydroxydiphenyl sulfone and the polyaryl tion of claim9, wherein the sulfone is 3,3'dimethyl-4,4 '-dihydroxydiphenyl sulfone and the phosphonate is phenyldichlorophosphine oxide.

tion of claim 9, wherein the sulfone is 3,3,5,5'

'tetramethyl-4,4'dihydroxydiphenyl sulfone and the polyaryl phosphonate is phenyldichlorophosphine oxpolyaryl 12. The fireproof,thermoplasticpolyester compositerephthalate, r

polyethylene sebacate and polyethylene adipate and a polyaryl phosphonate incorporated therein in an amount of 0.4-to 4.0 percent as phosphorus to said polyester, said polyaryl phosphonate having a degree of polymerization not less than 6 andjprepared by surface polymerization, of a compound of the formula:

I dissolved in water while stirring.

wherein R is aryl and X is chlorine or bromine dissolvedin a solvent with a diol component selected from the group consisting of a sulfone compound of the formula: I

wherein the benzene ring(s) may hear one or more lower alkyl groups and a mixture of said sulfone compound and at least one aromatic diol compound selected from the group consisting ofthe formulas:

wherein Y is allrylidene or cycloalkylidene having one to six carbon atoms and the benzene ring( s) may bear one or more lower alkyl groups as alkali metal salt (s) 

1. A fireproof, thermoplastiC polyester composition which comprises a polyester selected from the group consisting of polyethylene terephthalate, fiber-forming copolymerized polyesters containing not less than 80 mol % of ethylene terephthalate unit, poly1,4-cyclohexylidenedimethylene terephthalate, polyethylene sebacate and polyethylene adipate, and a polyaryl phosphonate incorporated therein in an amount of 0.4 to 4.0 weight percent as phosphorus to said polyester, said polyaryl phosphonate having a degree of polymerization not less than 6 and being prepared by reacting a diol component selected from the group consisting of a sulfone compound of the formula:
 2. The fireproof, thermoplastic polyester composition according to claim 1, wherein said sulfone compound is selected from the group consisting of 4,4''-dihydroxydiphenyl sulfone; 2,4''-dihydroxydiphenyl sulfone; 3,3''-dimenthyl-4,4''-dihydroxydiphenyl sulfone; 2,2''-dimethyl-4,4''-dihydroxy-5,5''-di-t-butyldiphenyl sulfone; 2,2''-dihydroxy-3,3''-dimethyldiphenyl sulfone; and 3,3'', 5,5''-tetramethyl-4,4''-dihydroxydiphenyl sulfone.
 3. The fireproof, thermoplastic polyester composition according to claim 1, wherein said aromatic diol compound is selected from the group consisting of hydroquinone; resorcinol; 4,4''-dihydroxybiphenyl,4,4''-methylenebisphenol; 4,4''-ethylidenebisphenol; 4,4''-isopropylidenebisphenol; 4,4''-cyclohexylidenebisphenol; 2,2''-methylene-bisphenol, 1,5-dihydroxynaphthalene; and 2, 7-dihydroxynaphthalene
 4. The fireproof, thermoplastic polyester composition according to claim 1, wherein the compound having the formula: is selected from the group consisting of phenyldichlorophosphine oxide, and phenyldibromophosphine oxide.
 5. The fireproof, thermoplastic polyester composition of claim 1 wherein R is selected from the group consisting of phenyl, tolyl, xylyl, and naphthyl.
 6. The fireproof, thermoplastic polyester composition of claim 1, wherein the diol component and the compound having the formula: are reacted in approximately equimolar proportions.
 7. The fireproof, thermoplastic polyester composition of claim 1, wherein the diol component is said sulfone compound.
 8. The fireproof, thermoplastic polyester composition of claim 1, wherein the diol component is the mixture of said sulfone compound and, at least one of said aromatic diols, said mixture containing more than 30 mol percent of said sulfone compound.
 9. The fireproof, thermoplastic polyester composition of claim 1, wherein said sulfone compound is 4,4''-dihydroxydiphenyl sulfone and said polyaryl phosphonate is phenyldichlorophosphine oxide.
 10. The fireproof, thermoplastic polyester composition of claim 9, wherein the sulfone compound is a mixture of 4,4''-dihydroxydiphenyl sulfone and 2,4''-dihydroxydiphenyl sulfone and the polyaryl phosphonate is phenyldichlorophosphine oxide.
 11. The fireproof, thermoplastic polyester composition of claim 9, wherein the sulfone is 3,3''dimethyl-4,4''-dihydroxydiphenyl sulfone and the polyaryl phosphonate is phenyldichlorophosphine oxide.
 12. The fireproof, thermoplastic polyester composition of claim 9, wherein the sulfone is 3,3'',5,5'' tetramethyl-4,4'' dihydroxydiphenyl sulfone and the polyaryl phosphonate is phenyldichlorophosphine oxide. 